Technical Field
The present invention relates to an array substrate and a manufacturing method thereof, and in particular, to an array substrate that is electrically connected to a source/drain electrode and a heavily doped region by using an etching stop pattern or auxiliary conductive pattern of a patterned auxiliary conductive layer and a manufacturing method thereof.
Related Art
Because a low temperature polycrystalline silicon (LTPS) thin-film transistor assembly has a property of relatively high mobility, the LTPS thin-film transistor assembly theoretically has better electrical property performance than that of an amorphous silicon thin-film transistor assembly. In an ordinary top gate LTPS thin-film transistor assembly structure, a source/drain electrode needs to pass through a contact hole in a dielectric layer, such as a silica layer, to come into direct contact with and be directly connected to doped polycrystalline silicon. However, when the contact hole is formed in the dielectric layer in an etching manner, if dry etching having a relatively low etch selectivity ratio is adopted, it would be easy to damage the doped polycrystalline silicon and further affect a state that the source/drain electrode is in direct contact with or is directly connected to the doped polycrystalline silicon. In another aspect, if the contact hole in the dielectric layer is defined by means of wet etching having a relatively high etch selectivity ratio, although it is less likely to damage the polycrystalline silicon, the wet etching has a disadvantage of incapability of forming a contact hole with a relatively small hole diameter and cannot be applied to a product having a high resolution (for example, high pixels per inch (PPI)). In addition, generally, an etching solution used for etching silica contains a hydrofluoric acid, which would easily generate an irremovable stain on a back surface of a glass substrate and further affect execution of a subsequent process, such as Cell process alignment and a laser lift-off process of a flexible substrate.